Method of making forms



D 1940- v s. T. PETERSON 2,224,196

METHOD OF MAKING FORMS Filed y 2,- 1939 WW7 M I/VI/ANTO/K? 5 Petersen,

Patented Dec. 10, 1940 UNITED STATES PATENT OFFICE 5 Claims.

This invention relates particularly to a method of and a means for producing a last for making shoes for deformed feet.

In its broader aspects, the invention also comprehends the idea of making a splint or cast of any part of the human body which is in need of correction, without involving danger to said body or without unduly confining injured or tender parts of the body.

Coming to the particular aspects of the invention, one of the objects of the invention is to provide a method of forming a shoe last in rigid form, which last has a shape and sir conforming substantially exactly t the contours of a foot, which foot is to be protected by a shoe made over said last.

Another object is to provide a method whereby a shoe may be made having a shape which is substantially exactly the complement of the surface of the foot or some particular portion thereof.

Although the invention is capable of being carried out in many difierent ways, so as to produce many difierent articles, the accompanying drawing shows but one of the products which may be obtained thereby and the method to be followed is described in connection with this drawing. A preferred embodiment of the invention is described in the following specification, while the broad scope of the invention is pointed out in the appended claims.

In the drawing:

Figure 1 is a sectional elevation showing one section of the mold, the foot to be fitted and the arrangement of parts at the outset of the method to be followed;

, Figure 2 is a partial elevation and partial sectional view of the mold and foot at the next 40 step in the method to be followed;

Figure 3 is a top plan view showing the completed mold embodying the negative impression of the foot;

Figure 4 is a sectional view of Figure 3, with a portion of the mold removed; I

Figure 5 is a plan view showing the positive cast of the foot made in th molding process;

Figure 6 is a cross section taken on the line 66 of Figure 5;

Figures"? and 8 are views of the positive cast or'pattern, smoothed over or corrected to make a continuous outline.

In carrying out the invention, the most important procedure is to obtain a correct negative 55 impression of the foot. This is not an easy matter since the foot is a soft and pliant member and in order to obtain an impression without. exerting any deforming pressure on the foot, it

is necessary to use the molding materials carefully. 5 The mold is made in three sections, i being the bottom section and 2 and 3 the vertical side sections respectively. The foot to be fitted is placed on the bottom section, as shown in Figure 1, the section being made of a fiowable material like 10 plaster of Paris. Resting'on this bottom section is a pair of square aligned bars 4 and 5, the bar 4 touching the toe of the foot and the bar 5 touching the heel of the foot. Then the side sections of the mold, 2 and 3, are built up around 15 the foot, these sections also being made of plaster of Paris. These side sections are in abutting relation along parting surfaces 6, defined by aplane normal to the bottom section I and passing substantially through the center of the foot. 20 After the bottom section i has been formed grooves are made across its side edges, that is the edges against which the sections 2 and 3 are to be placed. Section 2 or 3 will then be molded in place and grooves will be formed in the face 25 of this section against which the other section 3 or 2 is to be formed. Thus, it will be seen that when the sections are separated from each other, both of the sections 2 and 3 will have ridges matching with the grooves 1 in the bottom of sec 80 tion i, and one of the sections 2 and 3 will have grooves and the other ridges matching with those grooves. By virtue of these ridges and grooves the various sections may be accurately fitted together and brought into register with 35 each other after they have been disassembled and removed from the foot.

Having built up the sections around the foot and obtained a negative impression, the side sections are removed, the footis removed, the bars 40 i and 5 are removed and the sections reassembled as in Figure 3. They can be held together by wires ill, wrapped'therearound. At this point,

a continuous square bar I i is placed in the mold, through the openings left by the bars 4 and 5, 4 so that when the final positive cast or pattern is made in the mold, it will have this bar integral with it and projecting from its opposite ends as shown in Figure 5 of the drawing.

A fluid mass adapted to set, such as plaster of Paris or a liquid or plastic material of a flowable consistency, is poured into the mold at H, to form the positive cast l3.

After the pattern has been cast, any desired portions may be built up so as to remove pressure of the shoe from any given portion of the foot, and this building-up may be governed so as to leave as much or as little room as desirable in any given portion of the finished shoe. Wax

is sometimes used in this building-up operation but any material capable of adhering to the positive cast and susceptible to shaping may be used. In this building-up process, the toes of the pattern are smoothed over as at l5, Figure 7, to make a continuous outline and to give ample room in the shoe, later to be fashioned.

The finished positive cast is shown in Figure 8 and herein takes on the name of a pattern or a model. The projecting-extremities of the bar II are used as means for centering the pattern on a tail piece of a suitable copying-lathe.

The invention contemplates making a mold of any part of the body, in a manner similar to the mold just described, separating the mold, reassembiing the same and casting in the mold a pattern of the affected part of the body, A

splint composed principally of leather, or the as a last and suitable or other stiffening means could be incorporated in the splint, Such a splint would normally weigh about one-tenth as much as a plaster cast and would place less weight on the affected part while giving it just as good, if not better support. This specific phase of the invention has not been illustrated since it is wholly within the concept of the invention shown in Figures 1 to 8 inclusive.

While the inventioii has been described in detail, it is to be understood that many changes may be made therein without departing from the spirit of the same. i

I claim:

1. The process of constructing a rigid form conforming substantially exactly to a portion of a foot of the body which comprises placing a pair of aligned square bars in contact with the toe and heel respectively of the foot, making a negative impression of a portion of the foot and said bars, disassembling and removing said negative impression from the foot and bars, and again assembling the same without said foot and bars in place therein, placing a continuous square bar in said negative impression in a position formerly occupied by said pair of bars, and making a positive cast from said negative impression, said out including said bar.

2. The process of constructing a rigid form conforming substantially exactly to a portion of a foot of the body which comprises placing a pair of aligned square bars in contact with the formerly occupied ,by said pair of bars, making 2,224,1oe a a positive cast from said negative impression,

said cast including said bar, and correcting said positive cast to conform to the desired position conforming substantially exactly to a portion oi a foot of the body which comprises-the forming of a mold in three sections, thev bottom section being that section upon which the foot is placed, placing a pair of aligned square bars in contact with'the toe and heel respectively of the foot and resting on said bottom section, then forming sections of said mold on the opposite sides of the foot, which sections are divided along a parting surface normal to said bottom section, removing said sections from the foot and again assembling the same to constitute a negative impression, placing a continuous square bar in said negative impression in a position formerly occupied by said pair of bars, and making a positive cast from said negative impression, said cast including said bar.

4. The process of constructing a rigid form conforming substantially exactly to a portion of a foot of the body which comprises the forming of a mold in three sections, the bottom section being that section upon which the foot is placed, placing a pair of aligned square bars in contact with the toe and heel respectively of the foot and resting oncsaid bottom section, then forming sections of said mold on the opposite sides parting surface normal to said bottom section, removing said sections from the foot and again assembling the same to constitute a negative impression, placing a. continuous square bar in said' negative impression in a position formerly occupied by said pair of bars, making a positive cast from said negative impression, said cast including said bar, and correcting said positive cast to conform to the desired position of the foot.

5. The process of constructing a rigid form conforming substantially exactly to a portion of a foot of the body which comprises the form-.

ing of a mold in three sections,'the bottom section being that section upon which the foot is placed, placing a pair of aligned square bars in contact with the toe and heel respectively of the foot and resting on said bottom section, then forming sections of said mold on the opposite sides of the foot, which sections are divided along a parting surface normal to said bottom section, removing said sections from the foot and again assembling the same to constitute a negative impression, placing a. continuous square bar in said negative impression in a position formerly occupied by said pair of bars, and introducing a fluid mass, adapted to set, into contact with the negative impression to form a positive cast, said cast including said bar.

SHANNON T. PETERSON.

of the foot, which sections are divided along a 

